The CAN-SPAM Act also directed the Federal Communications Commission to adopt rules designed to protect mobile service customers from unwanted commercial messages. On August 4, 2004, the Commission adopted a general prohibition on sending commercial messages to any address referencing an Internet domain associated with wireless subscriber messaging services.

There have been legal challenges to anti-spam laws. Opponents have raised two arguments. Their first is that state spam laws violate the Commerce Clause of the U.S. Constitution by putting an unfair burden on out-of-state business interests and by creating inconsistent state-law requirements. Their second argument, which has also been used to attack "junk fax" statutes, is that these laws unreasonably restrict commercial free speech.

In State v. Heckel, 143 Wash. 2d 824, 24 P.3d 404 (2001), the Supreme Court of Washington held that state's anti-spam law did not violate the Commerce Clause. In doing so, it noted that the law was directed at senders who used a Washington-based computer or targeted Washington residents, and concluded that the benefits of the law--namely, promoting truthful headers and routing information--outweighed the burdens it placed on senders. 

In Ferguson v. Friendfiinders, Inc., 94 Cal. App. 4th 1125, 115 Cal. Rptr. 2d 258 (2002), the California Court of Appeal, Second District, reached a similar result, holding that state's anti-spam law did not violate the Commerce Clause.

In MaryCLE v. First Choice Internet Inc., 166 Md. App. 481, 890 A.2d 818 (Md. Ct. App. 2006), an intermediate appeals court overruled a trial court and held that the Maryland Commercial Electronic Mail Act did not violate the Commerce Clause.

However, in Jaynes v. Commonwealth, No. 062388 (Va. Sup. Ct., September 12, 2008), the Supreme Court of Virginia unanimously reversed a criminal conviction under that state's anti-spam law. The alleged offense was intentionally falsifying the sender's routing information. The court concluded that since the law was not limited to commercial electronic mail, it could be used to prosecute those who exercised their First Amendment right to disseminate political speech under names other than their own. It held that the law was overly broad and therefore unconstitutional.

To read the full text of a jurisdiction's anti-spam laws, click on the link below.

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